Let’s get this out of the way: this documentary is not a film about Los Tigres del Norte. The band is there as a catalyst, setting in motion a story about the inmates of Folsom, a prison that has been mythologized in song and record. The event has a specific tie to the legendary show Johnny Cash gave 50 years before, but by the time the credits roll, this will be on the back of your mind. The main story is much more powerful.

Directed by Tom Donahue and written by Zach Horowitz and Los Tigres themselves, the film follows the lives of a handful of prisoners as they recount their story and their relationship with the music of the norteño legends. The inmates talk candidly about their situation for being committed and their hopes and dreams, some of which remain in their minds, and others which are long gone. As they recount their stories, they are matched by songs from Los Tigres’ two sets at Folsom, many dealing with immigration and violence, as they have long since dedicated their musical output to subjects dealing with real-life of Mexicans on both sides of the border.

As each story gets told, we begin to see a bigger picture of what the documentary’s thesis is. Many of the people interviewed had turned to crime because of their place in society – namely being poor and undocumented. Drugs and guns prove to be a common denominator in many of these people’s stories, and many of them end up in prison because something in their lives had gotten out of hand. While none of the inmates deny their involvement in some serious crimes, we come to understand how they were shaped to take the road that led them behind bars. At the core of the documentary is the notion that humans are equal and even the most severe of crimes don’t have to mean the end of someone’s life through incarceration. One subject that keeps coming back through these testimonies is family – how the actions of these individuals have damaged their own people and how they wish they could undo it for the sake of their loved ones. It’s heavy and quite emotional.

As stated, Los Tigres Del Norte themselves are not the focus of the doc, but there’s an aspect of their music that takes center stage throughout At Folsom Prison. One of the biggest qualities of Los Tigres’ music is their talent for narrative lyrics that convey not only relatable situations; their songs become living art entities that shine through with poetic flair even at its most realistic. The way songs like “La Jaula de Oro,” “La Bala,” and “La Baraja Bendita” unfold a story working charmingly in the film, not only reflecting the stories told by the prisoners but also the way they take a new life when heard through people who have lived similar situations.

Of course, for the musically curious, the centerpiece of the film is “Prisión de Folsom,” the cover of the famous Johnny Cash song. The song was translated and adapted with the help of singer-songwriter (and wife of Johnny Cash’s son, John Carter Cash) Ana Cristina, making it as typical and extraordinary as any of the Tigres greatest hits. It brings to mind the similarities between the sensibilities of Cash’s songwriting and country music with norteño and Los Tigres del Norte.

Los Tigres Del Norte At Folsom Prison is a story about how things change and how they also stay the same, but mostly it’s a story of the darkness of humanity and the light can come through at any moment.

September 16 at 11:20 p.m. ET: This article has been updated. An earlier version used an incorrect term for immigrants.